The house was still flooded I take it? Sometimes you can feel very calm, yet under the surface (even hidden for yourself) feel restless. Perhaps the shark attack never really surprised you, and is what you expect, while feeling secure they won't be able to harm you.
The children's position is alas a bit of overload detail for me... but perhaps you can make more out of it if you look up
http://www.dreammoods.com/dreamthemes/bodyparts.htm and whether it was left or right.
I gathered the boat was just stable and floating without movement from your first description, which is why I made the positive image conclusion: calm water, you floating stable on it. That someone is feeling calm does not necessarily mean you will be without emotions regarding this. Perhaps you may end up feeling supported, and having that positive emotion flood your world. So, the seeing of water/emotions does not need to mean you will be "overemotional"... just that it's not a situation that you will look at as an emotionless robot.
Whether you saw a shark in a movie recently or not, does not signify much imo. It might trigger the brain to pick such a symbol over another possibility, but doesn't need to.
Blessings